Table 4.

Sensitivity analysis with an intra-trial correlation coefficient of 0.8.

Null model	Hedges g	p	AIC	BIC
	− 0.11	0.091	132.82	142.68

Moderator variable	QM	p	AIC	BIC
Task	6.93	0.031*	130.43	142.70
Polarity	2.97	0.227	134.29	146.56
Target location	3.53	0.740	138.58	160.24
Return electrode	4.42	0.352	134.42	151.43
Timing	2.82	0.244	133.94	146.21
Current density	0.39	0.534	134.03	146.30
Duration	0.34	0.563	133.51	145.78
Blinding	1.14	0.768	136.30	153.32

Number of studies = 53, number of effects = 88. QM = Moderator test, AIC = Akaikes information criterion, BIC = Bayesian information criterion.